The invention relates to a cartridge for setting devices, consisting of a pot-shaped plastics material housing having a surface, which comes into contact with the inner contour of the cartridge chamber in the setting device, and a sealing cover, which closes off the open end of the seating body, and a cylindrical section, which protrudes into the interior of the housing.
Cartridges of the type mentioned are used in setting devices, especially in powder force-driven setting devices, of different types. In order to achieve as high an economic efficiency as possible, plastics material is advantageously used to produce such cartridges. In the event that cartridges of this type, which are connected with one another to form magazine strips, are used, a more rapid setting cycle is achieved than in the case of setting devices, operated with individual cartridges. It is important that individual cartridges, as well as cartridges connected together into a magazine strip, are constructed so that operational malfunctions of the setting device, such as those when parts or residues of the cartridges remain behind in the cartridge chamber of the setting device, cannot occur.
A cartridge of the aforementioned type is disclosed, for example, in EP 0525613 B1. This known cartridge consists of a pot-shaped, plastics material housing and a sealing cover, which closes off housing at its open end, and of a cylindrical section, which protrudes into the interior of the housing. The opening of the housing has an edge strip, which has undercuts, in which the correspondingly-shaped side edges of the sealing cover lock, on the mutually facing inner surfaces.
It is a disadvantage of the known cartridge that the connection between the sealing cover and the housing sometimes is inadequate. For example, it is possible that, due to the deformations arising during the ignition of the cartridge, the sealing cover falls off the housing, so that malfunctions in the setting device are caused. As a result, the setting device has to be dismantled, which takes considerable time. Especially in the case of setting devices for serial applications, where cartridges, connected into magazine strips, are used, such malfunctions have a serious effect.
It is a further disadvantage of this known solution that the manufacture of such a cartridge with a snap mechanism is not economic, since the undercuts in the housing as well as in the sealing cover make additional steps necessary in the production of the cartridge and require a greater expenditure for tools.
It is an object of the invention to provide a cartridge, which can be used trouble-free in setting devices independently of the respective pressure relationships. In addition, it is possible to manufacture the cartridge economically.
Pursuant to the invention, this objective is accomplished owing to the fact that the housing has at least one recess in the region of its surface at a distance from its open end and at least partially in the radial projection region of the cylindrical section of the sealing cover.
Owing to the fact that a relatively high pressure and a high temperature, in comparison to the surroundings, result in the interior of the housing during the ignition of the cartridge, the housing is deformed. During this deformation, the inner contour of the cartridge chamber forms a limitation in the form of a die. In the regions, which are bounded by the unchanged surface, there is practically no deformation of the housing. In the region of the recess, the latter is filled at least partially and the interior of the housing is consequently expanded. Since the recess is at least partially in the radial projection region of the cylindrical section of the sealing cover, this leads to an at least partial radial expansion of the interior of the housing in the radial projection region of the cylindrical section of the sealing cover. The cylindrical section of the sealing cover yields under the pressure and the high temperature and expands radially in the same region. Owing to the fact that the recess is disposed at a distance from the opening of the housing, a region, which is expanded less radially, remains between the region, expanded radially by the ignition of the cartridge, and the opening of the housing. Both regions together form a positive locking between the housing and the sealing cover, which prevents the sealing cover falling out during the ignition of the cartridge.
Viewed in the radial direction, the recess can be disposed anywhere. Preferably, however, it is open towards the outer periphery of the housing, since this is helpful for producing it economically.
From the point of view of the production of the cartridges and the deformation behavior of housing and sealing covers, the recess advisably is constructed in the shape of a wedge.
An axial length of the recess, which corresponds to 0.2 to 0.8 times the diameter of the cylindrical section, has proven to be particularly advantageous for an optimum positive connection between the housing and the sealing cover.
So that the deformation relationships are optimum, the depth of the recess, measured radially, preferably corresponds to 0.05 to 0.2 times the diameter of the cylindrical section. Under these conditions, a good positive connection between the housing and the sealing cover is assured and there is no overstressing of any material, such as the sealing cover during the ignition of the cartridge.
In order to ensure that a possible falling out of the sealing cover during the ignition of the cartridge in the axial direction is counteracted by adequate resistance, the recess is advisably disposed at a distance, which corresponds to 0.1 to 0.5 times the diameter of the cylindrical section.
The recess preferably extends over at least a portion of the periphery of the housing in order to achieve the best possible connection between the sealing cover and the housing. In particular, when the recess extends over the whole of the periphery of the housing, the deformation due to the annular expansion, which is uniform over the whole of the periphery, has an optimum effect on the positive connection.
In order to achieve the best possible centering of the sealing cover, for example, also during the installation, the axial length of the cylindrical section preferably corresponds to 0.2 to 0.6 times the diameter of the cylindrical section.
To ensure that the manufacturing process is as cost-effective as possible and achieves adequate stability of the sealing cover, the latter, pursuant to the invention, preferably is made from a metal, such as steel or brass.
In accordance with a further proposal of the invention, several cartridges are connected with one another into a magazine strip, so that the cartridges can be supplied automatically and, with that, a setting cycle, which is more rapid than that of singly supplied cartridges, becomes possible.
The invention is described in greater detail below by means of an example and a drawing, in which